Improvement in safety key-holder for door look



FRANKLIN J. MAY, 0F MORRISANIA, NEW YORK, ASSIGNOR TO HIMSELF l AND J. G. BARNUM, OF SAME PLACE.

Lema Parent Na. 62,865, dated March 12, 1867.

IMPROVEMENT IN SAFETY KEY-HOLDER FOR DOOR LOGK.

'EO/ALL WHOM IT MAY CONCERN:

Be it known that I, F. J. MAY, of Morrisania, in the county of Westchester, and State of New York, have invented a new and improved Attachment to Locks; and I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilled in the art to .make and use the scme,.rei`erence being had to the accompanying drawings, forming part of this specification.

The present invention relates to a nenr and improved attachment to door locks, more particularly, the object being to prevent the key, if left in the lock when locked, from being turned upon the outside of the door, which object is secured, as will be obvious from the following detail description of the same. In the accompanying drawings- A Figure 1 is a view of the front plate of a Iockcasing having my improved attachment applied thereto; and

Figure 2, an end view of the lock.

A, in the drawings, represents the lock-casing, and B the hole for the insertion ofthe key in the lock to lock and unlock it. C, the key, and D its shank. E, a plate hung upon a pin, a,'to the front plate F of the lock-casing, so as to swing over the key-hole of the same. This plate E has a circular or arc-shaped notch, or way, G, cut in it, which is concentric, or nearly so, with the centre pin a, upon which it -swings, and is at such a distance therefrom that the said plate can swing over and interlock with the shank of the key H, a pawl hung hung on plate E. This pawl, at its lower end, is weighted, so that it will always assume a vertical position, and thus by its upper end come against the shank of the key, which at that point or part of its length, against which it strikes or bears, is made square. I, a stop-pin for the pawl H, which prevents the pawl from being moved by the turning of the key in the lock.

The operatio'n of the attachment above described is as follows: After the key has been turned in the properA direction to lock the lock, let the plate E drop over the same into the position shown in iig. 1, when the pawl coming against the square portion of such key, it is then rendered impossible to turnthe key in the lock, either by its handle or by inserting any tool suitable therefor in the opposite side of the lock; thus, as is obvious, acting as a perfect safeguard against the unlocking of a door lock from the outside of the door t0 which such lock is applied, as is manifest lwithout; any further explanation. In lieu of hanging the attachment directly to the casing of a lock as has been above described, it may be applied to the door over the key-hole to the same, and in the use of my improved attachment it will be generally so applied.

I claim as new, and desire to secure by Letters Patent- The weighted pawl H,in combination with plate E, operating directly against the square shank of the key,

substantially as herein represented and described.

FRANKLIN J. MAY.

( Witnesses:

ALBERT W. BROWN, Tano. Tuscn. 

